Fundamental Study on the Electrodes for Alkali Metal Thermoelectric Converter (3rd Report, the Performance of Current Collection Structure with Porous Metal)

The alkali metal thermoelectric converter (AMTEC) is an efficient device for the direct conversion of heat to electricity. A new method to supply thermal energy to beta”-alumina solid electrolyte (BASE) tubes is proposed in this paper. Porous metal inserted between a high-temperature thermal source and the BASE tubes not only collects current generated from electrodes but also enhances the heat transfer. An experimental study has been conducted on the disturbance of vapor flow through the porous metal. Its effect on the AMTEC performance has been examined. The calculated results indicate that the sodium vapor flow resistance converted into temperatre difference is in the range from 20 K to 50 K and the expected increase of power density with porous metal current collection structure is ~50%. The influence of potential drop along the electrode is also discussed.